When dilute $H_2SO_4$ is added to an alkaline solution of protein,a violet color is obtained. What is this test called?

Write a note on amino acids.

The increasing order of $pKa$ of the following amino acids in aqueous solution is $Gly, Asp, Lys, Arg$.

The correct structure of the dipeptide gly-ala is

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ solution of the product obtained by heating a mole of glycine with a mole of chlorine in the presence of red phosphorus generates a chiral carbon atom.
Reason $R$: $A$ molecule with $2$ chiral carbons is always optically active.
In the light of the above statements,choose the correct answer from the options given below:

Identify the amino acid which has $-NH_2$,$-CO_2H$ and $-CONH_2$ groups.